upgrading to a 8.25 rear end from 7.25. what to know?

[SonOfaTomP]

let me preface by saying, i don't know that much about rear differentials.

the rear Diff on my 88 Civ Gran Fury has begun to whine quite loudly. from all i've heard this rear diff doesn't seem well liked.

now i'm not really trying to make a hot rod or anything, i just use this car as usual daily transportation. weighing my options. upgrading to a 8.25 seems like a popular choice. possibly cheaper than fixing the 7.25

what gearing do these cars need? and from what cars is the rear axle compatible? not far from me is a 8.25 from a 97 Cherokee with 3.55 gears. only 300 bucks. and there was a police 8.25 up in PA i'm unsure if is still available from a Diplomat.

 

[AMC Diplomat]

I think the Cherokee axle might be too wide and you'd have to get the axle tubes cut down and get shorter axle shafts.

I'm not a Jeep guy. So I don't know for certain.

If you can get an 8 1/4 off of any Aspen, Volare, Diplomat, etc., it'll bolt right in.

Who cares about the gearing. If you find an 8 1/4 that fits, buy it, you won't regret it. The 7 1/4's in these cars are all stupid low gears anyways. You're not going to find a cheap axle with a crazy ratio. I wouldn't even worry about it. Just find an axle that fits and put it in.

The 7 1/4s suck. I ended up scrapping my 7 1/4, it was in my way after the swap and I couldn't find anyone who wanted it for free. The howl was eliminated and now I can hear all the other problems the car has.

There are B body axles out there you can make fit, but it's so much easier to slap in an interchangeable assembly and just have it fit.

Don't forget you'll need a shorter drive shaft. I got mine out of a Volare. Axle is out of an old Diplomat police car. (and yeah i lost a sway bar bushing while i was installing that and slapped in a cheap rubber one, im a complete hack, i had left over green paint and painted the axle too)